Current Status of the Asteroid Explorer HAYABUSA
- Firing ion engine and starting second phase
orbit maneuver to return to Earth -

February 4, 2009 (JST)

Japan Aerospace Exploration Agency (JAXA)

The Japan Aerospace Exploration Agency is doing its best to operate the Asteroid Explore "HAYAUBSA" to return it to Earth in June 2010.
After leaving the orbit around the asteroid "ITOKAWA," the ion engine of the HAYABUSA was cut off on Oct. 18, 2007 (Japan Standard Time, JST) to complete the first phase orbit maneuvering for returning to the Earth. Since then, the HAYABUSA has been in a coast flight, but today we reignited the ion engine for a powered flight at 11:35 a.m. (JST) after activating its reaction wheel and establishing the three axis attitude control. We will continue to gradually accelerate the HAYABUSA until around March 2010 to carry out the second phase orbit maneuvering for returning it to the Earth.
From April to June 2010, we will guide the HAYABUSA, which will have reached much closer to the Earth by then, to further come near to the earth's orbit with higher accuracy, and plan to carry out the re-entry of its capsule into the atmosphere in June 2010.
The total accumulated operation time of the ion engine reached 31,000 hours, and the total engine generation for orbit maneuver(*1) was 1,700 meters per second (m/s) to date. The HAYABUSA still has enough thrust power and propellant. Some 400 m/s more of engine generation for orbit maneuvering is necessary for returning to the Earth.
We are continuing to pay careful attention to our onboard equipment and are doing our utmost to operate the HAYABUSA with the greatest care.

(*1) engine generation for orbit maneuver: volume of acceleration by an ion engine